Hemiptera
Family Characters
STERNORRHYNCHA
Psyllidae: Diagnostic characters: small (2-5 mm); 2 pairs of wings in both sexes,
held roof-like over body, forewing often thicker than hind wing; resemble
miniature cicadas; strong jumping legs; antennae 10-segmented; tarsi
2-segmented, with 2 claws.
See the Psylloidea Web Page from the USDA's, Systematic Entomology Laboratory. Psyllids, or jumping
plant lice, feed on phloem sap, and are usually very species specific; a very
few produce galls such as the hackberry nipple gall psyllid, Pachypsylla celtidismamma, and Psylla magnicauda. The nymphs live
inside the galls. Eggs laid shallowly in plant tissue and covered with wax.
Nymphs do not closely resemble adults and produce copious powdery wax.
Adults resemble miniature cicadas and are active jumpers and fliers. Two
important pest species, both introduced from Europe, are the pear psylla, Psylla pyricola, and the apple sucker, Psylla mali. Nymphs feed on
axils of leaves and fruit and produce copious honeydew on which fungus grows;
infected trees shed leaves and fruit.
Aleyrodidae: Whiteflies. Diagnostic characters:
minute (2-3 mm); 2 pairs of wings in both sexes; forewings about equal in size
to hind wings; body and wings covered with a white waxy powder.
See the USDA's Systematic Entomology Laboratory Whitefly Web Page. 1st instar nymphs are
active, but later nymphs are sessile and scale-like. The group is
abundant in the tropics. One important species affects citrus - fungus
growing on honeydew interferes with photosynthesis. Other species are important
greenhouse pests.
AUCHENORRHYNCHA
Cicadidae: Diagnostic characters: large insects with large wings; forewing
membranous; 3 ocelli.
Cicada immatures live in the ground and feed on plant roots. The immature life
span last for several years in the dog-day cicadas and up to 13 or 17 years in
the periodical cicadas. Dog-day cicada adults
emerge during the "dog days" of summer in the northern hemisphere -
late July to September in Minnesota.
Examples:
A dog-day cicada, Tibicens resh; male T. resh showing operculum of
sound producing organ; female showing ovipositor. Size range in cicadas, the giant Pomponia imperitoriafrom
Malaysia and the small Pacarina
puella from Texas; Linnaeus'
17-year cicada, Magicicada septendecim; a Costa Rica species, Zammara tympanum, with pronotal flanges.
Cercopidae: Diagnostic characters: small jumping insects; hind
tibiae with 1 or 2 stout spines, and usually a circlet of spines at apex.
Spittle bugs or froghoppers are best know for the frothy spittle produced from
the anus and abdominal glands of the immatures, which covers them while they
feed on grasses. These insects are very common, especially in meadows, but only
a few might be considered pests. Examples of cercopid diversity, 1, 2; tibia showing arrangement of spines.
Membracidae: Diagnostic characters: small jumping insects;
pronotum projecting backwards over abdomen, often highly developed (especially
in tropical species).
Tree hoppers feed on trees and shrubs where they display a rather narrow host
range. Tropical species are known for the bizarre ornamentation of their
pronota. The adaptive value of these ornamentations include crytic resemblance
to thorns and twigs, sexual display, and apophysectomy. Some species show a
primitive form of sociality, with the female tending her eggs and offspring
while they mature. Examples of membracids, showing remarkable diversity of
pronota: a common Minnesota species; Costa Rican, Mexican, and Brazilian examples; other, mostly Neotropical, examples, 1, 2.
Cicadellidae: Diagnostic characters: hind tibiae with 1 or more
rows of small spines.
Leafhoppers comprise a very large, species diverse, and economically important
family. They feed on the leaves of plants, which in crop species causes
economic damage by sapping the plant of nutrients, damaging xylem and phloem
cells, damaging twigs through female oviposition, or by vectoring plant viruses
and other diseases. Like cicadas, they produce sound, but this sound is usually
not audible to humans. The many species have been placed in some 18
subfamilies. A typical cicadellid from Minnesota; hind tibia showing rows of spines; head, showing position of
antenna in relation to eye (on front of head between eyes and head without a
carina). Two colorful species from Costa Rica.
Fulgoroidea: Diagnostic characters: antennae arising on sides of head beneath eyes,
separated from front of head by a vertical carina.
The planthoppers constitute a group of about a dozen families in North America,
all recognized by the antennae separated from the front of the head by a vertical carina and thus arising beneath the eyes. They feed on a
rather wide range of plant types, but few or of any economic importance. A few
exemplary families are listed below:
Delphacidae: Hind tibia showing large apical spur. This is the largest family. Its species are
small and often have short wings. One species was a pest on sugarcane in
Hawaii.
Derbidae: Apache dageeri, Minnesota. Derbids
feed on woody fungi. Most species are tropical.
Cixiidae: Cixius basalis, Minnesota. These are
mostly tropical, with some species feeding underground on grass roots.
Dictyopharidae:
Scolops,
Minnesota; two tropical examples,
Costa
Rica,
Venezuela.
These feed
mainly on grasses. Many have the head produced into a slender process, but some
others don't.
Tomado y editado
de :
http://www.entomology.umn.edu/museum/links/coursefiles/Hemip%20characters.html
